Antarctica characteristics, climate, flora, fauna, countries

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Sherman Hoover
Antarctica characteristics, climate, flora, fauna, countries

The Antarctica It is a continent located at the south pole of the planet, whose lands are 98% covered by ice. It has a relief with large mountain ranges, plains, depressions and plateaus, most of it hidden by a 2,500 m thick layer of ice.

Its numerous subglacial lakes next to the ice cap, store 70% of the planet's fresh water. This is the coldest and driest continent, with temperatures of almost -90 ºC, winds of 100 km / h and annual rainfall of 200 mm..

Satellite map of Antarctica

The human population in Antarctica is primarily restricted to the scientific, technical and support staff of scientific stations. This population is fluctuating, hovering between 1,000 and 10,000 people, increasing in the summer season and decreasing in the southern winter..

In total, about 20 countries have scientific stations in Antarctica, some with several stations, such as Argentina, Chile, Russia, the United States, China, Australia and Spain. In the marine areas of the region there are abundant species of fish, cetaceans and other organisms, representing the greatest biodiversity of this continent.

On its coasts are seals, sea lions, penguins and flying seabirds. While its diversity of flora is scarce, the most abundant being fungi, lichens, mosses, liverworts and algae..

Article index

  • 1 Characteristics of Antarctica
    • 1.1 Location and extent
    • 1.2 Ice and fresh water
    • 1.3 Relief
    • 1.4 Biodiversity
  • 2 Climate
    • 2.1 Temperature
    • 2.2 Precipitation
  • 3 Human population
    • 3.1 System of government
  • 4 Flora
    • 4.1 Plants
  • 5 Fauna
    • 5.1 Mammals
    • 5.2 Birds
    • 5.3 Fish
    • 5.4 Insects and arachnids
  • 6 Countries with bases in Antarctica
  • 7 References

Characteristics of Antarctica

Photo of Antarctica with seal of the species Lobodon carcinophagus

Location and extension

This continent covers 14.2 million square kilometers within the Antarctic Circle at the south pole of the Earth. The geographic south pole is located almost in the center of this continent.

Ice and fresh water

Antarctica

Antarctica contains about 90% of the ice and 70% of the fresh water of the Earth, forming a polar cap in the south of the planet. This cap is made up of 26.5 million cubic kilometers of ice.

This ice sheet goes from almost zero in coastal areas to 4,000 m thick. In addition, ice forms floating shelves around 75% of the Antarctic coastline..

Today those platforms are collapsing due to the effect of warm water currents that undermine them from below. Because these platforms hold back the flow of inland glaciers into the sea, their melting is a problem..

This is due to the fact that when the platforms decrease, the glaciers drift into the sea and thin, deepening the thaw of the continent. Therefore, the sea level rises, all caused by global warming of the Earth. According to estimates, this ice retreats at a rate of 1.6 km per year.

Relief

Relief of Antarctica. Source: euphro / CC BY-SA (https://creativecommons.org/licenses/by-sa/2.0)

Due to the extensive and deep ice sheet, Antarctica is the continent with the highest average elevation. The Antarctic relief reaches an average elevation of 2,300 meters above sea level, with the peculiarity of actually containing two layers of relief.

On the one hand the relief of the rocky base under the ice, and on the other that formed by the surface of the ice cap. The underlying relief beneath the ice sheet is very rugged, ranging from coastal plains at sea level to large mountain ranges..

It is an intricate network of archipelagos, gulfs, lakes, mountain ranges and plains, the highest point being Mount Vinson at 4,892 meters above sea level. While the lowest is the Bentley subglacial trench at 2,400 m below sea level (with 4,000 m of ice on top).

Location of the Vinson Massif

On the other hand, in Antarctica there are around 400 subglacial lakes, the largest being Lake Vostok with a surface area of ​​12,500 km². This lake is under a 4,000 m ice sheet, located in a depression 500 m below sea level.

Similarly, the Gamburtsev mountain range is 1,200 km long, 3,200 meters above sea level and is completely covered by ice. Thus, all the variability of the continent's relief is hidden due to the ice sheet that permanently covers it..

This in turn creates a radically different surface relief, dominated by icy plateaus, jutting mountain ranges, and coastal plains. The area with less thickness of ice is oriented towards South America, although in its center is the subglacial Bentley Trench.

The point with the largest ice cap in the world is located in the Astrolabe basin, in the area facing Australia.

Biodiversity

Humpback whale in Antarctica

Given the extreme low-temperature conditions, life is highly restricted in Antarctica, being the least biodiverse continent. In most of its territory there are only microorganisms, especially algae, bacteria and archaea trapped in subglacial lakes and ice.

In the coastal areas there is more life, since the climate is tempered by the oceanic influence. However, the number of terrestrial species is very low, restricting plant life to some species of vascular plants and a diversity of mosses.. 

Likewise, there are other groups of organisms such as fungi. For its part, the animal is represented by insects, birds and marine mammals that visit the coasts. 

Weather

Antarctica has the coldest climate on the planet, due to its location and the average height of its territory. Here there is no sunlight during the austral winter that goes from April to September (around 60 hours of Sun in this month).

The rest of the year the Sun remains low on the horizon, reaching a cumulative number of hours of Sun of less than 3,000 hours. On the other hand, in this territory surface winds of 100 km / h are frequent.

However, despite the scarce sunlight, ultraviolet radiation is intense on this continent, due to the hole in the ozone layer that periodically forms over this territory, allowing the passage of a greater amount of this radiation..

Temperature

The average maximum temperature is around -46.3 ºC, with the maximums being reached in December and hovering around -13 ºC. While the average minimum is -52 ºC, with the coldest natural temperature recorded on Earth, -89 ºC taken in the Russian station on the subglacial lake Vostok

Precipitation

Rainfall in Antarctica is in the form of snow, snowing 284 days a year, reaching only about 200 mm per year. This precipitation is concentrated mainly on the coasts, that is, it is an extremely dry region, a cold desert.

Human population

Researchers taking rock samples in Antarctica. Source: Ministry of Foreign Relations from Peru / CC BY-SA (https://creativecommons.org/licenses/by-sa/2.0)

There is controversy regarding when was the first time that human beings visited Antarctica, with various countries competing for the honor. In a recent study it was established that to date, almost two thirds of the Antarctic territory has received at least one human visit.

This research collected 2.7 million records of activity of some kind in this area since at least 1819. In this context, the area that remains the most alien to human impact is the eastern part, which is the most inhospitable.

However, regular human activity is concentrated in the 1% of the ice-free territory, which is where conditions are most favorable. Human presence is fundamentally restricted to research stations in various countries, as well as tourist trips and the periodic presence of fishermen..

The more or less permanent human population is between 1,000 in winter and 10,000 in summer. In the Argentine scientific station Esperanza, the first person registered in this continent was born in 1978, an Argentine named Emilio Marcos Palma..

Argentina has the largest native population in the continent, with 8 children born in the Esperanza station. Followed by Chile with 3 children born at the Frei Montalva station.

Government system

Emblem of the Antarctic Treaty. Source: Alakasam. / CC BY-SA (https://creativecommons.org/licenses/by-sa/3.0)

Antarctica is governed by an international agreement signed by 38 countries that make up the Antarctic Treaty System. Various nations maintain territorial claims over areas of this continent, including France, United Kingdom, Norway, New Zealand, Australia, Chile and Argentina.

Flora

In most of the Antarctic territory there is no vegetation, it is restricted to the coastal strips. In these areas there is a tundra ecosystem, with a predominance of mosses, lichens, fungi, algae and grasses..

Terrestrial algae are found as Prasiola crispa, as well as 750 species of fungi and 400 of lichens. Many species are endemic, such as the fungus Cryomyces antarcticus, able to withstand harsh conditions, such as high UV radiation.

Prasiola crispa. Source: Wilfried Bauer / CC BY-SA (https://creativecommons.org/licenses/by-sa/3.0)

Plants

Antarctic hair grass (Deschampsia antarctica). Source: Lomvi2 / CC BY-SA (https://creativecommons.org/licenses/by-sa/3.0)

The most diverse groups are the bryophytes with about 125 species of mosses and liverworts. While vascular plants only have three species that exclusively inhabit the Antarctic peninsula.

One of them, the annual bluegrass (Poa annua) is an introduced grass, therefore there are only two native species. These are the Antarctic hair grass grass (Deschampsia antarctica), and a caryophylliaceous, the Antarctic pearl (Colobanthus quitensis).

Fauna

The most obvious fauna of Antarctica is the marine one, especially birds, seals and penguins, apart from there are also tardigrades, mites and nematodes.

Mammals

Lobodon carcinophagus

The mammals that inhabit this continent are marine, either adapted to life between the coast and the sea or exclusively marine. Among the first are 7 species of seals and sea lions, such as the crabeater seal (Lobodon carcinophagus) and the leopard seal (Hydrurga leptonyx).

Hydrurga leptonyx

Others are the Weddell seal (Leptonychotes weddellii) and Ross's seal (Ommatophoca rossii). As well as the sea lion (Mirounga leonina) and the Antarctic sea lion (Arctocephalus gazella).

Arctocephalus gazella

Among the exclusively marine mammals are 10 species of cetaceans, including baleen and toothed whales. Among these is the largest existing animal on the planet, the blue whale (Balaenoptera musculus), the humpback whale (Megaptera novaeangliae) and the orca (Orcinus orca).

Orcas breathing

Birds

Macronectes giganteus

Numerous species of seabirds nest in Antarctica in spring, with populations of about 175 million. Among them is the wandering albatross (Diomedea exulans), the Antarctic pangasius (Stercorarius maccormicki) and the giant petrel (Macronectes giganteus).

Stercorarius maccormicki

However, penguins are the most representative birds, with 6 species making up a population of around 175 million specimens. One of these species is the emperor penguin (Aptenodytes forsteri), the largest and endemic to this continent.

Aptenodytes forsteri

There are also the Adelie penguin (Pygoscelis adeliae), which is the most abundant species on the continent, and the chinstrap penguin (Pygoscelis antarcticus).

Pygoscelis adeliae

Others are the macaroni penguin (Eudyptes chrysolophus), rockhopper penguin (Eudyptes chrysocome) and the gentoo penguin (Pygoscelis papua).

Eudyptes chrysolophus

Fishes

Fish species abound in the Antarctic Ocean, highlighting the suborder Notothenioidei or ice fish. Being the most abundant, they are characterized by having an antifreeze protein.

Insects and arachnids

Only one species of insect native to the Antarctic continent is known, it is a wingless dipteran with a scientific name Belgium antarctica. On the other hand, spiders and mites are also found in the consinent.

Belgium antarctica

Countries with bases in Antarctica

The first Antarctic station was installed in 1904 by Argentina known as Orcadas, and another called Esperanza. This country has 5 more permanent stations and 7 in summer and after Orkney, about 100 stations have been installed by about 20 countries.

Argentine station Orcadas in Antarctica. Source: Argentina.gob.ar (Government of Argentina) / CC BY 2.5 AR (https://creativecommons.org/licenses/by/2.5/ar/deed.en)

Chile has the President Eduardo Frei Montalva Base and 3 more permanent ones, as well as 5 summer bases. Spain has two scientific bases in the South Shetland Islands that operate in the summer.

Aspect in 2006 of the President Eduardo Frei Montalva Base. Source: Mefisto29 / CC BY-SA (https://creativecommons.org/licenses/by-sa/4.0)

Most of the stations are in the Antarctic Peninsula, since this is the most habitable area and closest to America. Another Ibero-American country with stations in Antarctica is Ecuador with the Pedro Vicente Maldonado scientific station on Greenwich Island..

Peru has the Machu Pichu Base on the 25 de Mayo Island (or King George Island), as well as Uruguay and Brazil. On the other hand, Russia has 5 stations, including Bellingshausen on the Antarctic Peninsula and Vostok on the other end of the continent..

The United States has the Amundsen-Scott base at the geographic south pole, built in 1956, which houses almost 50 people in winter and 200 in summer. It also has the MacMurdo base on Ross Island, with the largest human population of up to 1,258 residents, the Palmer base and 22 summer camps..

Mac Murdo Station; research center and behind Mount Erebus

China has four seasons in Antarctica, the first called the Great Antarctic Wall and the United Kingdom has two permanent seasons and three summer ones. There are also Australian (3), French (2), German (2), Indian (2) and South Korean (2) stations. As well as Norwegian (1), Italian (1), New Zealand (1), Polish (1), Romanian (1), Ukrainian (1), Japanese (1) and South African (1).

References

  1. British Antarctic Survey. Bedmap2. Natural Environment Research Council. (Viewed July 18, 2020). Taken from bas.ac.uk
  2. Mackintosh, N.A. (1960). The Pattern of Distribution of the Antarctic Fauna. Proceedings of the Royal Society of London. Series B, Biological Sciences.
  3. Peat, H.J., Clarke, A. and Convey, P. (2006). Diversity and biogeography of the Antarctic flora. Journal of Biogeography.
  4. Popov S.V., Lastochkin A.N., Masolov V.N. and Popkov A.M. (2006), Morphology of the Subglacial Bed Relief of Lake Vostok Basin Area (Central East Antarctica). Based on RES and Seismic Data. In: Fütterer D.K., Damaske D., Kleinschmidt G., Miller H. and Tessensohn F. (eds). Antarctica. Springer, Berlin, Heidelberg.
  5. Schiavini, A.C.M., Yorio, P.M., Gandini, P.A., Raya-Rey, A.N. and Boersma, P.D. (2005). The penguins of the Argentine coasts: population status and conservation. The Hornero.
  6. Smith, R. (1981). The earliest report of a flowering plant in the Antarctic ?. Polar Record.
  7. World Wild Life. Tundra. (As seen on July 15, 2020). Taken from: worldwildlife.org/biomes/

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